1. Field of the Invention
The invention relates to new products and to lubricants containing same. They are made by (1) reacting an aminoguanidine or its salt with an unsaturated monocarboxylic acid and (2) reacting the product of (1) with sulfur.
2. Discussion of the Prior Art
It is well known that, under certain conditions, metal parts being lubricated will rust. That is to say, when certain types of materials that are normally susceptible to deterioration by oxidation or by corrosion come into contact with various organic media, rust may form. Organic compositions in both the liquid and solid form can induce such corrosion or oxidation. For example, it is known that liquid hydrocarbons in the form of various fuel oils, such as petroleum distillate hydrocarbon fuels, lubricating oils, or greases therefrom, tend to accumulate considerable quantities of water when maintained for long periods of time in storage vessels; and when subsequently brought into contact with metal surfaces in their functional environments, deterioration of said surfaces as a result of rust and corrosion occurs. In addition, where such lubricating oils are incorporated into lubricants in the form of greases, similar deleterious results are encountered.
Many materials have been advanced for use as rust inhibiting additives to organic compositions. Several of these involve compounds comprising a nitrogen atom, such as the glyoxalidines (U.S. Pat. No. 2,668,100) and the like. Furthermore, amines such as the alkanolamines have been disclosed as being anti-rust agents per se. No known art, however, suggests that an effective product can be made by the reaction of materials to be set forth in detail hereinafter.